Conveyor system

ABSTRACT

A conveyor system particularly useful for handling domestic waste or the like is described. The conveyor receives dumped waste, conveys it up an incline, and dumps it into a receiving silo from which it may be discharged as desired. A dumping station prior to the silo can be employed for selectively removing articles from the waste. The conveyor comprises a plurality of carts mounted between rails forming a continuous loop track. The carts are interconnected by cables to form a continuous conveyor with the carts intermittently spaced along the cables. In order to drive the conveyor, a reversible chain drive is employed with a pair of pawls on separate portions of the chain so that they move in opposite directions along the extent of the track. The pawls permit passage of the carts when the pawls are moving in the reverse direction and they engage the cart when moving in a forward direction for driving the conveyor in a hand-over-hand fashion. A pair of such sets of driving pawls are provided on the two sides of the conveyor respectively so as not to interfere with a selectively openable bottom on the carts.

United States Patent Morgan et a]. 5] July 25, 1972 [54] CONVEYOR SYSTEMPrimary Examiner-Even C. Blunk Assistant Examiner-H. S. Lane [72]Inventors: George W. Morgan, 1400 Douglass, Space Anomey christie, p gHale 112, Anaheim, Calif. 92806; Douglas S. Whitney, 2616 E. Norm Place,Anaheim, Calif. 92800 [5 7] ABSTRACT A conveyor system particularlyuseful for handling domestic waste or the like is described. Theconveyor receives dumped waste, conveys it up an incline, and dumps itinto a receiving silo from which it may be discharged as desired. Adumping station prior to the silo can be employed for selectivelyremoving articles from the waste. The conveyor comprises a plurality ofcarts mounted between rails forming a continuous loop track. The cartsare interconnected by cables to form a continuous conveyor with thecarts intermittently spaced along the cables. In order to drive theconveyor, a reversible chain drive is employed with a pair of pawls onseparate portions of the chain so that they move in opposite directionsalong the extent of the track. The pawls permit passage of the cartswhen the pawls are moving in the reverse direction and they engage thecart when moving in a forward direction for driving the conveyor in ahand-over-hand fashion. A pair of such sets of driving pawls areprovided on the two sides of the conveyor respectively so as not tointerfere with a selectively openable bottom on the carts.

16 Claims, 10 Drawing Figures Patented July 25, 1972 3,679,045

4 Sheets-Sheet 2 Patented July 25, 1972 3,679,045

4 Sheets-s 5 Patented July 25, 1972 3,679,045

4 Sheets-Sheet 4 CONVEYOR SYSTEM BACKGROUND OF THE INVENTION In ourmodern day, affluent society great volumes of domestic wastes areproduced and discarded. This waste is a melange of the articles found inour homes and industries, and includes many salvageable commodities suchas waste paper, rags, glass, cardboard and a variety of reusable metals.Many, many of these articles are presently discarded and buried insanitary fill dumps. It is highly desirable in order to preserve ournatural resources and maintain the quality of the environment to reclaimand recycle as much of this reclaimable material as possible.

These waste materials are presently picked up in trucks or the like andhauled to a central dumping location where they are discarded. In orderto reclaim such materials it is desirable to present them to eithermanual or automatic sorting equipment in a relatively steady,controllable flow. In order to accomplish this, means are required forconveying the materials from the trucks as dumped, to some meteringarrangement for controlling the flow through the balance of the sortingsystem. The conveyor provided must accept a random selection ofmaterials in quite variable volume and having a large variety ofcomponents. The conveyor must be rugged, relatively large, and asinexpensive as possible, yet reliable in operation under the adverseconditions to which it is subjected. The conveyor should allow for easeof maintenance and replacement of components as may be required quicklyand easily without great precision in the replacement.

BRIEF SUMMARY OF THE INVENTION Thus in practice of this inventionaccording to a presently preferred embodiment there is provided aconveyor system having a continuous conveyor which is caused to conveyarticles by a pair of driving members in engagement with a portion of alength of the conveyor. The pair of driving members alternately engagethe conveyor in hand-over-hand fashion.

In a preferred embodiment the conveyor has a plurality of carts movingbetween rails and interconnected by a linear flexible drive. Drivingpawls engage the carts successively and alternately for driving thecarts in a forward direction between an article receiving portion and anarticle dumping portion of the conveyor.

DRAWINGS These and other features of the invention will be appreciatedas the same becomes better understood by reference to the followingdetailed description of a presently preferred embodiment when consideredin connection with the accompanying drawings wherein:

FIG. 1 illustrates in side schematic section a dumping station andconveyor constructed according to principles of this invention;

FIG. 2 is a perspective view of a cart in the conveyor FIG. 1;

FIG. 3 is a fragmentary view transverse to the conveyor of FIG. 1;

FIG. 4 is a schematic perspective view of the conveyor of FIG. 1;

FIG. 5 is a perspective of a means for driving the cans of FIG. 2; and

FIGS. 6A through 6E are schematic illustrations showing successiveoperation of the driving means for the conveyor.

Throughout the drawings like numerals refer to like parts.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 illustrates in sidesection, somewhat schematically, a dumping station and refuse conveyorconstructed according to principles of this invention. As illustrated inthis presently preferred embodiment a building 11 stands above groundlevel 12 and includes a subterranean portion where at least some of theoperations involved in practice of this invention may occur. At groundlevel a large opening 13, which is preferrably provided with closeabledoors (not shown), is provided along one side of the building. Refusetrucks have access to the opening 13 and are backed up to the openingfor discharging loads of refuse into the building. Such refuse dumpedfrom the trucks falls into the lower subterranean portion of thebuilding. If desired, a track mounted crane (not shown) can be providedalong the opposite side of the building from the opening 13 formanipulation of portions of the refuse as may be required and forassisting trucks in unloading.

Refuse dumped from the trucks falls to a receiving portion 14 of acontinuous conveyor running through the building. The receiving portion14 of the conveyor and the building 11 can be as long as desired toprovide the required number of dumping stations along its length so thatrefuse trucks do not have a prolonged vwait for access to the station.Such length is largely dependent, of course, on the volume of refuse tobe handled in the station. The refuse receiving portion of the conveyoris located in the bottom of a rectangular trough (not shown in crosssection) which may have sloping sides near the upper portion to form atype of temporary detention when large volumes of refuse areencountered, and further to funnel refuse from the truck-dumpingstations to the bottom of the trough.

A refuse conveyor system constructed according to principles of thisinvention extends along the bottom of the trough through the refusereceiving portion 14 of the structure. The conveyor comprises a pair ofparallel tracks 16, the loop course of which through the structure 11 isillustrated schematically in FIG. 1. A plurality of carts 17 or the likeare mounted for movement along the tracks 16 through the building. Thecarts 17 are intermittently or randomly spaced along the track withoutany required precise spacing therebetween. Because of the drivingmechanism hereinafter described, the carts need not be periodicallyspaced. The carts are interconnected by flexible cables 18 (FIGS. 2 to4) extending in a continuous loop along the extent of the tracks. Theinterconnection of the carts 17 is provided so that driving of one ormore of the carts anywhere along the continuous loop results in all ofthe carts traveling in synchronism along the tracks through the entiresystem.

The tracks 16 extend in a continuous loop through the refuse receivingportion 14 of the building. The tracks then proceed upwardly along aninclined ramp 19 to a sufficient elevation that refuse handled in thestation can flow by gravity through a flow control station to aconveyor. Adjacent the top of the ramp 19 is an emergency dumpingstation or bin 21 over which the tracks pass. The tracks then pass overa silo 22, and in a portion 'over the silo the tracks curve into areverse direction in a vertically extending are 23 which serves toinvert the carts 17 so that any refuse therein falls into the silo 22 asindicated by the arrow 24. The carts, which are now inverted, travelalong the tracks 16 along the upper portion of the building, includingthat portion above the ramp 19 and the refuse receiving portion 14. Atthe far end of the building from the silo 22, the tracks make twosweeping turns to bring the carts 17 down from the upper portion of thebuilding and into an upright orientation as they again enter the portionof the loop through the refuse receiving portion 14 of the building.

Refuse dumped into the receiving portion 14 is picked up by the carts l7and conveyed up the ramp 19, over the emergency dumping bin 21, whichmay be employed as hereinafter described, and is dumped into the silo 22as the carts invert. The slope of the ramp 19 is preferably greater thanthe typical angle of repose of refuse so that refuse is carried upprincipally as contents of the carts with little refuse being pushedahead of the carts. Any excess falls over the back of the carts and ispicked up by subsequent carts.

The refuse in the silo 22, which can be of any desired vertical extent,passes downwardly and between a pair of hingemounted doors 26 which canbe controllably moved together or apart for controlling the flow ofrefuse out of the bottom of the silo. Refuse passing through the openingbetween the doors 26 falls into a disintegrator 25 which is in the formof a plurality of interlocking star wheels turning at different angularvelocities so that there is a shearing or tearing action therebetween.This serves to break up boxes of refuse, tear open plastic or paperbags, and bend or break large objects. The disintegrator does not grindor shred the refuse in the usual sense, but serves to break up thelarger aggregations of refuse for subsequent sorting to recover valuablearticles such as paper, metal, glass, rags or the like. From thedisintegrator 25 the refuse falls onto a conveyor 27 in the form of aconventional moving belt extending transverse to the greater extent ofthe building 11.

FIG. 2 illustrates in perspective one of the carts 17 between theparallel rails 16. FIG. 3 illustrates in fragmentary front view one ofthe sides of the cart 17. Each of the carts in a preferred embodimentcomprises a substantially flat bed 31, the principal portion of which ismade up of a bottom door 32 connected to the bed 31 along its forwardedge by a plurality of hinges 33. A catch or latch 34 indicatedschematically in FIG. 2 is provided at the rear portion of the door 32.The latch 34 is a conventional spring-loaded catch or the like thatpermits the door 32 to open when the weight thereon exceeds somepreselected value. The bed of the car 17 is bounded along its rearwardedge by a vertically extending back 36, the height of which is selectedfor containing a desired volume of refuse within the cart. Bed of thecart is bounded along its side edges by vertical sides 37 graduallyincreasing in height from front to rear, or other similar sides that mayserve to contain refuse within the cart.

Along each side of the cart is a relatively heavy-duty frame member suchas, for example, a heavy steel casting 38. The side member such as, forexample, a heavy steel casting 38. The side member 38 is rigidlyconnected to the side 37 of the cart and serves to mount a pair ofwheels 39 which fit within the open channel of the substantiallyU-shaped rail 16. Since the opposed rails 16 are in the form of U-shapedchannels, the wheels 39 engage the lower portion of the channel whetherthe cart is in its upright position as illustrated in FIG. 2 or in itsinverted position when returning through the building as illustrated inFIG. 1. Thus, the wheels 39 and side members 38 support the weight ofthe cart and its contents, if any, from the tracks 16 during operationof the system.

During travel of the carts through the refuse receiving portion (FIG; 1)they travel above the bottom of the trough. Thereforea downwardlyextending lip 41 or scraper is provided along the leading edge of thebed 31 for minimizing the refuse left in the bottom of the trough.

The side frame members 38 each include a strong bumper block 42 on theback of the cart and, if desired, these blocks may be interconnected bya transverse stiffening rib 45 to prevent racking and maintain the planprofile of the cart substantially rectangular. The side frame members 38also include conventional cable clamps 43 which during operation areconnected to the flexible steel cables 18 that interconnect the carts inthe loop extending around the building. It will be apparent that in lieuof a pair of cables, one or more chains or similar flexible lineardriving members can be employed with suitable clamps or connectingdevices between the chain and the carts 17. Preferably, the entire sidemember 38 is readily removable from the body of the cart so that cableclamps, flanged wheels, bumper blocks and the like can be replacedquickly and easily for inexpensive maintenance without disabling theentire conveyor system for any substantial period of time.

It should be noted that maintenance requirements are well accommodatedin the embodiment illustrated in FIG. 1. Thus, for example, access tothe carts is readily provided from beneath the ramp 19, or, ifpreferred, from an elevated work station on the portion of the loopalong which the carts return in their inverted position. An emergencydumping station 46 is provided at one end of the building 11 so that, atsuch times as the conveyor must be stopped for maintenance, dumping ofrefuse trucks into the dumping station 46 can be continued withoutcompletely filling the refuse receiving portion 14 through which theconveyor passes. Refuse accumulated in the emergency dumping station 46can then be transferred to the conveyor system at a convenient time byany of a variety of means, such as, for example, conveyors, a crane, atractor, or gravity chutes. Maintenance is also accommodated on theconveyor 27 by elevating the conveyor a substantial distance above floorlevel in the region through which it passes, and by providing doors inthe region between the bottom of a silo 22 and the conveyor 47. Thisallows maintenance of the doors 26 and conveyor 27, as well as theopportunity to clear articles from the disintegrator 25.

In order to drive the conveyor of interconnected carts through the loopillustrated in FIG. 1, some way must be provided for applying forces tothe cables 18 interconnecting the carts. A major problem in cable-drivensystems has always been a reliable, sturdy and economical means forengaging the cable to apply such a force to it. A plurality of wrapsaround a large drum or sheave can be employed in some situations,however, this is impractical where, as in the illustrated embodiment,the plurality of carts or the like are intermittently spaced along thelength of the cable and firmly attached thereto. Means for repeatedlygrabbing the cable and pulling it along have not been satisfactory forlong-term, reliable use. Provision of driving lugs along the length ofthe cable or use of a chain or the like can provide a means for driving,however, these require a degree of periodicity in the lugs for steadyengagement by the driver in order to obtain substantially smooth motion.

In order to obtain substantially continuous motion as illustrated in theconveyor system, means are provided for engaging each successive cartand driving it along the length of a portion of the track. Since thebalance of the carts are connected to the one being driven, the entireloop of carts is therefore drawn around the track. Because each of thecarts is firmly connected to the cables 18, engagement with the cartsamounts to engagement with the cables without any necessity of actuallygripping the cables with a driver.

It is preferable in construction and operation of a system as providedin practice of this invention that the carts be intermittently orrandomly spaced along the length of the cables rather than at periodicintervals so that no great care need by taken in where a cart ispositioned when it is replaced, for example. Intermittent positioning ofthe carts is also desirable since in some applications it may bepreferred to have the carts relatively closely spaced, and in othersituations, a relatively long spacing between the carts is quiteacceptable. The preferred driving means is therefore suitable forengaging successive carts independent of the degree of spacingtherebetween.

The driving mechanism is provided along the ramp 19 since during thisportion of the travel of the carts around the loop the loads aregreatest on the conveyor system. During this stretch, the loaded cartsare being drawn uphill and the cables interconnecting the carts mustalso transmit the loads imposed on following carts as they pick uprefuse in the receiving portion 14 of the station. Around the balance ofthe loop, with the short exception of the portion over the emergency bin21 and silo 22, the carts are unloaded and merely idling along the trackto return to the receiving portion. Cable sheaves (not shown) areprovided around the turns such as the are 23 and return bends at theentrance of the receiving portion 14 of the loop. It is preferable thatthe load on the cables at this portion of their travel be relativelylight so that damage to and by the cable clamps does not become aproblem.

The means for driving the string of carts is illustrated sche maticallyin FIG. 4, and also in the sequence of positions illustrated in FIGS. 6Athrough 6E which show the operating arrangement. A detail of the drivingsystem is illustrated in perspective in FIG. 5. The driving systemcomprises a pair of substantially identical driving chains 51 onopposite sides of the conveyor. Each of the chains is in a continuousloop around a driven sprocket wheel 52 and in idler sprocket wheel 53.The axes of the sprocket wheels 52 and 53 approximately intersect thetwo interconnecting cables 18 so that the two operating reaches of thechains 51 are respectively above and below the cable 18 by approximatelyequal amounts. It will be apparent to one skilled in the art thatadditional idler pulleys or the like can be employed as desired so thatthe drive sprocket wheels 52 are out of line with the cables. The twodriven sprocket wheels 52 are mechanically interconnected so as to drivein synchronism, and both are connected to a reversible driving motor 54.In the schematic illustration of FIG. 4, the driven sprocket wheels areshown aligned with the cables 18 and no specific mechanicalinterconnection is provided, however, it will be apparent that if thedrive sprocket wheels 52 are out of the plane of the cables 18 at thispoint, they can both be mounted on a single shaft. Other equivalentdriving arrangements can, of course, be provided. It will also beapparent that if desired instead of using a reversible electric motor 54a single direction motor can be employed with a direction reversingmechanism between the motor and the drive sprocket wheels.

A driving lug 56 is provided on each reach of each chain 51 for a totalof four driving lugs, two on each side of the carts. The upper lugs aredesignated 56A and the lower lugs 56B for describing the mode ofoperation. Since the upper and lower driving lugs 56A and 56B are onseparate reaches of the chain 51, it will be apparent that asillustrated in FIG. 4, when the reversing motor 54 is rotating in aclockwise direction the upper driving lug 56A is traveling forwardly,that is, in the same direction as the carts and the lower lug 56B ismoving in the reverse direction. Such a driving arrangement is alsoillustrated in FIG. 6A wherein the carts move from left to right in thedrawing. As illustrated in this figure, one of the carts 17A connectedby the cables 18 to other carts 17 is being driven by a lug 56A in theforward direction. Each of the lugs is provided with a mechanism forengaging the bumper block 42 (FIGS. 2 and 3) on the back of a cart ashereinafter described and illustrated in FIG. 5. During this portion ofoperation the upper lug 56A is driving forwardly and the lower lug 56Bis returning on the lower reach of the chain 51.

As the driving continues, as illustrated in FIG. 6B, the cart 17A isdriven further along the reach of chain 51 by the upper lug 56A and thelower lug 56B reaches the cart 17A and passes it by, as illustrated inFIG. 6C. Meanwhile the next cart 17B is approaching since it isconnected to the first cart 17A by the cables 18.

When the driving lug 56B passes the second cart 178 and is in a positionimmediately behind the cart, as illustrated in FIG. 6D, the reversingmotor 54 (FIG. 4) is signaled to reverse direction. FIG. 6D illustratedthe instant of reversal when the chain 51 is not moving, and the lugs56A and 56B are both in engagement with the respective carts 17A and17B. Reversing of the drive causes the driving lug 56B in engagementwith the cart 17B to proceed in the forward direction, carrying the cart178 along with it. Meanwhile the upper lug 56A on the returning reach ofthe chain moves in the reverse direction and the first cart 17A passeson along the loop drawn by the cables 18. Driving of the second cart 173through the span between the sprocket wheels 52 and 53 brings a cart 17Cforward for engagement by the upper driving lug 56A in a sequencesubstantially the same as that hereinabove described. Thus, duringoperation the two driving lugs 56A and 56B on each of the chains 51successively engage successive carts for pulling them forwardly in whatcan be considered a hand-over-hand fashion. Thus, the two lugs 56A and56B alternately engage successive carts, and upon engagement, reversedirection so that the conveyor is constantly driven in the forwarddirection.

FIG. 5 illustrates in perspective cutaway a pair of the driving lugs 56Aand 568 in that portion of their travel along the two reaches of thechain 51 where they are adjacent each other. These lugs are viewed froma rearward direction, that is, as if the carts advanced from right toleft in the drawing. In a preferred arrangement, the chains 51 areconventional roller chains and the driving lugs each comprise a body 57having ears 58 at its forward and aft ends for connection to the chainin lieu of conventional links thereof. By substituting the driving lugsfor links of the chain, the driving forces are maintained substantiallyin line with the chain so that no substantial twisting is encountered.The body 57 of each of the driving lugs is provided with alongitudinally extending groove 61 along both its upper edge and itslower edge. Engaging each of the grooves 61 is a flange on asubstantially E-shaped guide rail 62. The guide rail 62 extends parallelto the track 16 and the flanges 63 prevent the driving lugs fromshifting laterally relative to the carts.

Mounted on each of the bodies 57 is a substantially triangular tongue orpawl 63. The pawl is spring loaded in a conventional manner so as to bebiased toward an extended position as illustrated in FIG. 5 andresiliently movable to a retracted position for passing a cart. Thus asa driving lug traveling rearwardly relative to the carts reaches a cart,the sloping ramp 64 on the rearward portion of the pawl 63 engages thecart and depresses the pawl in substantially the same manner a lock bolton a door operates. When the spring loaded pawl passes behind a cart itis biased outwardly and snaps back to its original extended position.When the lug is driven forward by the forward face 66 on the pawl, whichis normal to the extent of the chain, engages the bumper block 42 (FIG.2) on the rear of the cart.

Referring again to FIG. 63, when the lower driving lug 56B reaches thecart 17A the pawl (not shown in FIG. 6) is retracted by engagement withthe cart and remains retracted as it passes the cart, snapping back intoits extended position after the cart has passed such as in the positionillustrated in FIG. 6C. Similarly, the pawl retracts as the lug 56Bpasses the cart 178 and snaps back into its extended driving positionwhen the cart 17B is passed.

A switch (now shown) is incorporated in each of the driving lugs toprovide a signal each time the pawl springs back to its extendedposition. These signals are employed for reversing the motor 54 (FIG. 4)when both lugs 568, that is, on opposite sides of the cart, have theirpawls extended. An extremely sim ple control system is all that isrequired since all that is needed is to sense when both pawls areextended for the second time in each cycle. Thus, the pawls aredepressed once upon engagement with the first cart and spring toanextended position when the cart is passed. The signal indicating thatthe pawl has been extended can be employed, for example, to set aflip-flop and then when the pawl is extended for the second time whenthe second card is passed, the flip-flop can be reset and the drivemotor reversed. The signals from the driving lugs on both sides of thecarts are employed for reversing the motor so that it is assured thatboth pawls are engaged with the sides of the cart so that both sides aredriven and the cart is not twisted in the track. Since the driving lugsare positioned opposite each other on the two chains 51, and the two aredriven in synchronism, the carts are maintained in a substantiallystraight line at all times.

The driving arrangement for the conveyor is simple and reliable and canbe built with quite heavy components at relatively low expense since itis not necessary to have precision machining of any of the parts. Sinceonly moderate precision is required, manufacture is inexpensive andmaintenance is minimized. Worn or damaged driving lugs are readilyremoved from the drive chain and replaced as required.

Referring again to FIG. 1, at the upper end of the ramp 19 an emergencydumping bin 21 is provided prior to the portion of track over the silo22. When the carts l7 reach the region above the dumping bin 21, thebottom door 32 in the cart is no longer supported by the bottom of thetrough through which the cart travels. When normal refuse is beinghandled, the strength of the spring catch 34 (FIG. 2) is sufficient tokeep the door 32 closed, and refuse in the cart remains therein fordumping into the silo when the cart inverts at the end of the conveyor.Ifon the other hand a heavy object, such as, for example, a large pieceof concrete happens to be in the refuse, the additional weight causesthe door 32 to fall open over the emergency bin 21 and permit therefuse, including the heavy object to fall into that bin. Bulky objectsor articles that might damage the refuse disintegrator 25 are preferablypicked from the refuse by the crane (not shown) in the refuse receivingportion 14 of the station. If such an article should be carried by thecarts into the region of the emergency dumping bin, an operator canindependently release the latch 34 either by an independent triggeringmechanism (not shown) beneath the ramp at the entrance to the bin, or byaddition of force to the door while it is over the bin.

The far side of the dumping bin includes a camrning portion 67 thatengages the open door (if any) hanging from the bottom of the cart andcams it to a closed position for return to the refuse receiving portionof the station. if desired, the door can be closed at some later pointin the travel when the cart is inverted. Any heavy or bulky items dumpedinto the emergency dumping bin 21 are retrieved individually, and theremaining refuse in the bin is then dumped into the stream going throughthe silo by opening a door 68 therebetween. in this manner, heavy orbulky items are removed from the flow of refuse for preventing damage tothe disintegrator 25.

Because of the bottom dumping feature provided for separating heavy orlarge articles, a continuous central cable interconnecting the carts isnot practical and a single cable also suffers from an inability toretain the carts in line in case of a load that would skew one of themin the tracks. Such a system would be quite susceptible to jamming.Similarly a central driving system midway between the carts haslimitations in maintaining the carts in a non-skewed path. A centraldriving system beneath the carts is also quite susceptible to cloggingdue to accumulation of refuse in the mechanisms. Provision is thereforemade for driving from the two sides of the carts.

One specific example of a conveyor system constructed according toprinciples of this invention has been described and illustrated herein.Many modifications and variations will be apparent to one skilled in theart. Thus, for example, a conveyor having driving mechanism as hereindescribed may be employed for raw materials or finished products insteadof in a refuse collection station. The exact layout of such a stationcan also be varied, such as, for example, by providing taller or largersilos, multiple silos, or auxiliary functions, such as, fumigation,dehydration or the like. Many modifications and variations will beapparent to one skilled in the art, and it is therefore to be understoodthat within the scope of the appended claims the invention may bepracticed otherwise than as specifically described.

What is claimed is:

1. Means for driving a continuous conveyor comprising:

a plurality of driven members connected intermittently along theconveyor;

first means for engaging a first one of the members for driving it in afirst direction;

second means for engaging a second one of the members for driving it inthe first direction; and

means for moving the first means in a second direction opposite to thefirst direction when the second means is moving in the first direction,and for moving the second means in the second direction when the firstmeans is moving in the first direction.

2. Means for driving a continuous conveyor as defined in claim 1 furthercomprising:

means for reciprocating the first and second means alternately in thefirst and second directions.

3. Means for driving a continuous conveyor as defined in claim 1 whereinthe distance of movement of the second means in the first direction inengagement with a second one of the members is independent of thedistance of movement of the first means in engagement with a first oneof the members in the first direction.

4. Means for driving a continuous conveyor as defined in claim 1 whereinthe first and second members adjacent each other in succession along theconveyor and wherein engagement of the first means with the first memberis in alternation with engagement of the second means with the secondmember.

5. Means for driving a continuous conveyor as defined in claim 1 whereinthe first means is alternately engaged and disengaged while the secondmeans is alternately disengaged and engaged respectively.

6. Means for driving a continuous conveyor as defined in claim 1 furthercomprising:

third means for engaging the first one of the lugs for driving it in thefirst direction in synchronism with the first means for engaging; and

fourth means for engaging the second one of the lugs for driving it inthe first direction in synchronism with the second means for engaging.

7. Means for driving as defined in claim 6, wherein the first and secondmeans for engaging are on one side of the conveyor and the third andfourth means for engaging are on the opposite side of the conveyor.

8. Means for driving a continuous conveyor as defined in claim 1 whereinthe first and second means for engaging each comprise pawl means forpassing the members when moving in the second direction arid engagingthe members when moving in the first direction; and wherein the meansfor moving comprises a reversible drive means connected to the firstmeans for engaging and the second means for engaging.

9. Means for driving a continuous conveyor as defined in claim 8 whereinmeans for moving further comprises:

a continuous loop linear flexible drive extending along the conveyor;

a drive pulley for driving the linear flexible drive and connected tothe reversible drive means; and

an idler pulley;

and wherein the first means for engaging comprises a first pawl engagedwith one portion of the linear flexible drive between the drive pulleyand idler pulley, and

the second means for engaging comprises a second pawl mounted on theother portion of linear flexible drive between the idler pulley anddrive pulley.

10. A conveyor system comprising:

a continuous loop track;

a plurality of intermittently spaced article moving members movablealong the track;

means for interconnecting the article moving members in a continuousloop extending around the track;

first means for engaging alternate ones of the article moving membersirrespective of their spacing adjacent a portion of the track fordriving said alternate members in a first direction; and

second means for engaging the other alternate ones of the article movingmembers irrespective of their spacing adjacent the portion of track fordriving said other alternate members in the first direction.

11. A conveyor system as defined in claim 10, wherein the trackcomprises a parallel set of rails;

the article moving members each comprise a cart mounted between therails; and

the means for interconnecting comprises a linear flexible drive.

12. A conveyor system as defined in claim 11 wherein each of the cartscomprises:

a substantially open forward end;

a substantially closed rearward end; and

a selectively openable bottom.

13. A conveyor system as defined in claim 12 wherein the trackcomprises:

an article receiving portion;

an inclined drive engagement portion;

a cart inverting discharge portion; and

a return portion between the inverting portion and the article receivingportion. I

14. A conveyor system as defined in claim 13, further comprising dumpingstation between the drive engagement portion of the track and the cartinverting portion of the track for selectively opening the bottom of thecarts.

15. A conveyor as defined in claim 14, wherein the first and secondmeans for engaging each comprise:

pulley and the drive pulley respectively. 16. A conveyor as defined inclaim 14, further comprising: third means engaging alternate ones of thecarts in synchronism with the first means for engaging; and fourth meansfor engaging the other alternate ones of the carts in synchronism withthe second means for engaging; the first and second means for engagingbeing on one side of the carts and the third and fourth means forengaging being on the other side of the cans.

I i i t @7 3 UNITED STATES PATENT OFFICE CERTIFICATE OF CRECTIQN3,679,045 Dated Ju1y25, 1972 Patent No.

Inv n r(s) George W. Morgan, Douglas S. Whitney It is certified thaterror appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

Column 3, line 32, delete "The side member such as, for

, example, a heavy steel casting 38."

Column 4,' line- 42, "by" should be "be-n Column 8, line 7, and Column8, line 10', 'i'lugs" should be I -members-.

Signed and sealed this 17th'day of April 1975,

(SEAL) Attest EDWARD M.PLETCHER,JR. ROBERT GOTTSCHALK Attesting OfficerI Commissioner of Patents

1. Means for driving a continuous conveyor comprising: a plurality ofdriven members connected intermittently along the conveyor; first meansfor engaging a first one of the members for driving it in a firstdirection; second means for engaging a second one of the members fordriving it in the first direction; and means for moving the first meansin a second direction opposite to the first direction when the secondmeans is moving in the first direction, and for moving the second meansin the second direction when the first means is moving in the firstdirection.
 2. Means for driving a continuous conveyor as defined inclaim 1, further comprising: means for reciprocating the first andsecond means alternately in the first and second directions.
 3. Meansfor driving a continuous conveyor as defined in claim 1 wherein thedistance of movement of the second means in the first direction inengagement with a second one of the members is independent of thedistance of movement of the first means in engagement with a first oneof the members in the first direction.
 4. Means for driving a continuousconveyor as defined in claim 1 wherein the first and second membersadjacent each other in succession along the conveyor and whereinengagement of the first means with the first member is in alternationwith engagement of the second means with the second member.
 5. Means fordriving a continuous conveyor as defined in claim 1 wherein the firstmeans is alternately engaged and disengaged while the second means isalternately disengaged and engaged respectively.
 6. Means for driving acontinuous conveyor as defined in claim 1 further comprising: thirdmeans for engaging the first one of the lugs for driving it in the firstdirection in synchronism with the first means for engaging; and fourthmeans for engaging the second one of the lugs for driving it in thefirst direction in synchronism with the second means for engaging. 7.Means for driving as defined in claim 6, wherein the first and secondmeans for engaging are on one side of the conveyor and the third andfourth means for engaging are on the opposite side of the conveyor. 8.Means for driving a continuous conveyor as defined in claim 1 whereinthe first and second means for engaging each comprise pawl means forpassing the members when moving in the second direction and engaging themembers when moving in the first direction; and wherein the means formoving comprises a reversible drive means connected to the first meansfor engaging and the second means for engaging.
 9. Means for driving acontinuous conveyor as defined in claim 8 wherein means for movingfurther comprises: a continuous loop linear flexible drive extendingalong the conveyor; a drive pulley for driving the linear flexible driveand connected to the reversible drive means; and an idler pulley; andwherein the first means for engaging comprises a first pawl engaged withone portion of the linear flexible drive between the drive pulley andidler pulley, and the second means for engaging comprises a second pawlmounted on the other portion of linear flexible drive between the idlerpulley and drive pulley.
 10. A conveyor system comprising: a continuousloop track; a plurality of intermittently spaced article moving membersmovable along the track; means for interconnecting the article movingmembers in a continuous loop extending around the track; first means forengaging alternate ones of the article moving members irrespective oftheir spacing adjacent a portion of the track for driving said alternatemembers in a first direction; and second means for engaging the otheralternate ones of the article moving members irrespective of theirspacing adjacent the portion of track for driving said other alternatemembers in the first direction.
 11. A conveyor system as defined inclaim 10, wherein the track comprises a parallel set of rails; thearticle moving members each comprise a cart mounted between the rails;and the means for interconnecting comprises a linear flexible drive. 12.A conveyor system as defined in claim 11 wherein each of the cartscomprises: a substantially open forward end; a substantially closedrearward end; and a selectively openable bottom.
 13. A conveyor systemas defined in claim 12 wherein the track comprises: an article receivingportion; an inclined drive engagement portion; a cart invertingdischarge portion; and a return portion between the inverting portionand the article receiving portion.
 14. A conveyor system as defined inclaim 13, further comprising dumping station between the driveengagement portion of the track and the cart inverting portion of thetrack for selectively opening the bottom of the carts.
 15. A conveyor asdefined in claim 14, wherein the first and second means for engagingeach comprise: a pawl for engaging a cart when moving in the firstdirection and for passing a cart when moving in a second directionopposite to the first direction; said conveyor comprising: a continuousloop linear flexible drive; a drive pulley for the linear flexibledrive; an idler pulley for the linear flexible drive; and reversibledrive means connected to the drive pulley; and wherein the first andsecond drive pawls are connected to the continuous loop flexible drivein separate portions between the idler pulley and the drive pulley andbetween the idler pulley and the drive pulley respectively.
 16. Aconveyor as defined in claim 14, further comprising: third meansengaging alternate ones of the carts in synchronism with the first meansfor engaging; and fourth means for engaging the other alternate ones ofthe carts in synchronism with the second means for engaging; the firstand second means for engaging being on one side of the carts and thethird and fourth means for engaging being on the other side of thecarts.